Give a 99.5% confidence interval, for
μ
1
−
μ
2
given the following information.

n
1
=
25
,
¯¯¯¯
x
1
=
2.79
,
s
1
=
0.69

n
2
=
20
,
¯¯¯¯
x
2
=
2.82
,
s
2
=
0.63